Traditionally, textile fabrics, including clothes, have been cleaned with laundry detergents, which provide excellent soil removal, but can often make garments feel harsh after washing. To combat this problem, a number of fabric. conditioning technologies, including rinse-added softeners, dryer sheets, and 2-in-1 detergent softeners, have been developed. 2-in-1 detergent softeners have normally been the most convenient of these technologies for consumers, but many of these existing technologies still have disadvantages. One of the more effective technologies for this type of product, systems comprising cationic, polymers, softens quite well but can contribute to soil deposition, hindering the cleaning performance of the detergent.
Anionic soil release and antiredeposition polymers are often used to improve cleaning, but normally, the amount of certain types of anionic polymers added to a fabric conditioning system including cationic polymers is minimized. It is believed, without wishing to be bound by theory, that anionic polymers can complex with the cationic polymers and have a detrimental effect on softening.
Softening laundry detergent compositions have been disclosed in published U.S. Pat. Nos. 6,616,705; 6,620,209; and 4,844,821.
Washer added fabric softening compositions have been disclosed in U.S. Pat. Nos. 4,913,828 and 5,073,274. Fabric softener compositions have been disclosed in WO 00/70005 and U.S. Pat. No. 6,492,322.
Lazare-Laporte, et al., European Patent No. EP 0 786 517 discloses a detergent composition including (a) surfactant material, (b) amphiphilic carboxy containing polymer, and (c) uncharged polymer. A process for producing suspending liquid laundry detergents has been disclosed in Hsu, U.S. Pat. No. 6,369,018. Hsu discloses the use of cationic cellulose ether (polymer JR) in an anionic surfactant containing liquid detergent and further requires a polysaccharide polymer such as xanthan gum. As optional, Hsu et al. describe soil release polymers in encapsulated form.
A need remains for softening laundry detergent compositions including cationic polymers for improved softening achieved through adding the compositions in the wash cycle of automatic washing machines, while avoiding soil redeposition. Surprisingly, we have found that certain anionic polymers are compatible with cationic fabric conditioning polymers, allowing the formulation of products that give excellent softening without compromising cleaning performance.